Table 8.
Reliability coefficients of the Parent PKU-QOL questionnaire at baseline in the parent evaluable population (n = 253)
| Parent PKU-QOL scores | Cronbach’s α | ICC |
|---|---|---|
| Child health status | - | 0.59 |
| Headaches | - | 0.47 |
| Stomach aches | - | 0.41 |
| Tiredness | - | 0.58 |
| Irritability | - | 0.65 |
| Aggressiveness | - | 0.69 |
| Moodiness | - | 0.61 |
| Sadness | - | 0.48 |
| Anxiety | - | 0.60 |
| Lack of concentration | - | 0.63 |
| Slow thinking | - | 0.60 |
| Emotional impact of PKU | 0.63 | 0.78 |
| Practical impact of PKU | 0.74 | 0.76 |
| Social impact of PKU | 0.72 | 0.80 |
| Overall impact of PKU | 0.84 | 0.84 |
| Anxiety – blood test | 0.73 | 0.85 |
| Impact of anxiety – blood test | 0.76 | 0.78 |
| Anxiety – blood Phe levels | - | 0.79 |
| Financial impact of PKU | - | 0.78 |
| Information on PKU | - | 0.63 |
| Adherence to Phe-free protein supplements | - | 0.42 |
| Management of Phe-free protein supplements | - | 0.61 |
| Practical impact of Phe-free protein supplements | 0.77 | 0.66 |
| Guilt if poor adherence to Phe-free protein supplements | - | 0.59 |
| Relationships within family because of Phe-free protein supplements | - | 0.59 |
| Adherence to dietary protein restriction | - | 0.29 |
| Management of dietary protein restriction | 0.85 | 0.78 |
| Practical impact of dietary protein restriction | 0.82 | 0.79 |
| Food enjoyment | - | 0.35 |
| Guilt if dietary protein restriction not followed | - | 0.70 |
ICC: Intraclass Correlation Coefficient; Phe: phenylalanine; PKU: phenylketonuria; QOL: quality of life. Reliability coefficients ≥0.70 are set in bold type.